The present invention relates to a protective bag for a vehicle occupant's head and, more particularly, to a bag which can be inflated along a window of a side door in the event of a lateral impact or roll-over situation. In detail, it relates to a protective bag for a vehicle occupant's head comprising two sheets which are superposed on each other and joined together along their peripheries to form a vacancy extending in a longitudinal direction of a vehicle, wherein the two sheets are connected to each other by a connecting line within the vacancy.
A protective bag for a vehicle occupant's head is disclosed in WO96/26087, particularly, FIG. 1 and FIG. 9 thereof. The bag has a vacancy comprising a duct extending from a front end to a rear end thereof and a plurality of cells communicated with the duct and extending downwardly. Between the adjacent cells, an occupant-side sheet and a vehicle body-side sheet are joined.
According to the bag disclosed in WO96/26087, gas flows into the duct through a rear end thereof so that the cells are inflated in order from the rearmost one in a longitudinal direction of the vehicle. Therefore, the frontmost cell is inflated with significant time lag behind the rearmost cell.